UV-Triggered Cascading Degradation of Silicone Elastomer via Self-Fluoride Amplification.

UV-triggered on-demand degradable materials offering accurate and remote control of material lifetime, are emerging as vital element for applications such as self-destructive soft robotics for hardware security, triggerable transient electronics, and data protection systems. However, previously reported UV-initiated materials face challenges, including i) poor scalability with limited penetration depth of UV light, ii) incompatibility with UV-blocking materials, preventing generation of reactive moieties for degradation. This study proposes a locally UV-triggered, synergistic F^- self-amplification system that enables rapid, complete, and on-demand degradation of silicone elastomer composite, even with embedding UV-blocking particles. This is achieved by introducing a self-immolative F^- amplifying molecule (FIA) and photo-induced F^- generator, diphenyliodonium hexaflurophosphate (DPI-HFP) into the silicone elastomer which amplifies F^- through F^--induced network of reactions. The F^- amplification mechanism is validated through spectroscopic, thermal and chemical analysis, and the composite shows excellent mechanical properties with elongation over 450% and low Young's modulus of ≈60 kPa. Rapid UV-triggered degradation occurs within 60 min even with embedding 33 wt.% of magnetic particle. Furthermore, a magnetically actuated soft robot is fabricated exhibiting various motions and on-demand degradation, underscoring the potential of this material platform for expanding the scope for UV-triggered degradable system across various fields.